On Thursday, Wigan manager Roberto Martinez criticised Birmingham for making an offer for the player that "doesn't look serious" and speaking publicly about their interest in N'Zogbia, who recently made his debut for France.

But Birmingham have returned with an improved offer and Wigan are now ready to let N'Zogbia, 24, leave the DW Stadium.

"Wigan Athletic can confirm that they have accepted a much improved offer from Birmingham City for France winger Charles N'Zogbia, which has now met the club's valuation," read a club statement. "The player has now been given permission to speak with Birmingham."

N'Zogbia joined Wigan from Newcastle for a fee of £6 million in February 2009 and has made 50 Premier League appearances for the Latics, scoring six goals.

Although Martinez recently dismissed suggestions that he had fallen out with the player, he did concede that N'Zogbia was not in the right frame of mind to feature in the opening-day defeat at the hands of promoted Blackpool.